Apparatus for disposing of solid wastes

ABSTRACT

Apparatus for disposing of solid wastes having a kiln sealed at its feed and discharge ends. A compacted slug of waste material is collected at the feed end and when the slug is of sufficient size and density, it is pushed into the kiln combustion chamber where it is burned. The combustion gases enter a secondary combustion chamber which is provided with an afterburner. After complete combustion, the gases exhaust through a stack. The kiln is provided with a unique air distribution system and is formed of a steel outer jacket and a spaced inner refractory jacket which has a plurality of openings to permit the feeding of oxygen or other combustion supporting gas from outside the kiln to the inside of the kiln. The kiln rotates about its axis to improve the combustion of the waste material. The burning is in a controlled atmosphere since the discharge end of the kiln is water sealed. The ash from the combustion chamber drops onto a water submerged conveyor for automatic removal from the system while maintaining the seal of the controlled combustion furnace.

Unite States Patent 91 Sargent et a1.

[ APPARATUS FOR DISPOSING OF SOLID WASTES [75] Inventors: Edward A. Sargent, Brookville,

N.Y.; Arthur J. Doner, Kearny, NJ.

[73] Assignee: Grumman Ecosystems Corporation,

Bethpage, NY.

22 Filed: July 13, 1973 21 Appl.No.:379,190

3,682,117 8/1972 Rousseau 110/14 11] 3,842,7 62 51 Oct. 22, 1974 Primary E.\'(1Hli)ltl'K011110111 W. Sprnguc Attorney, Agent, or Firm-Samuelson & Jacob 57] ABSTRACT Apparatus for disposing of solid wastes having a kiln sealed at its feed and discharge ends. A compacted slug of waste material is collected at the feed end and when the slug is of sufficient size and density, it is pushed into the kiln combustion chamber where it is burned. The combustion gases enter a secondary combustion chamber which is provided with an afterburner. After complete combustion, the gases exhaust through a stack. The kiln is provided with a unique air distribution system and is formed of a steel outer jacket and-a spaced inner refractory jacket which has a plurality of openings to permit the feeding of oxygen or other combustion supporting gas from outside the kiln to the inside of the kiln. The kiln rotates about its axis to improve the combustion of the waste material. The burning is in a controlled atmosphere since the discharge end of the kiln is water sealed. The ash from the combustion chamber drops onto a water submerged conveyor for automatic removal from the system while maintaining the seal of the controlled combustion furnace.

7 Claims, 13 Drawing Figures 1 APPARATUS FOR DISPOSING OF SOLID WASTES The invention relates to apparatus for disposing of solid wastes efficiently and economically. In particular, the invention is directed toward providing such an apparatus which will produce little or no ecological damage.

Prior art devices for incinerating solid waste material are either of the open type or of the sealed batch feed type. The open type incinerator is open to the ambient atmosphere or environment and, as a consequence, it is difficult to control combustion precisely or to prevent fly ash and other atmospheric contaminants from entering the air. The closed type incinerator is free of the disadvantages of the open type but, up to now, has only been available for batch operation. Batch operation requires that a fixed amount of material be fed to the incinerator, burned and removed. Then a new batch is fed to the incinerator.

Broadly, the present invention overcomes the disadvantages of both of these systems. It permits almost continuous processing of solid wastes in a closed system and, for all practical purposes, the process is continuous. A cylindrical kiln is sealed from ambient atmosphere and is tilted downward a slight amount toward its discharge end. Material is fed from a hopper to a cylinder in which a ram is mounted. The ram compresses the material and when a slug of predetermined size and density is collected in the cylinder, the feed end door opens and the slug is pushed into the kiln. While the feed end door is open to receive the slug, the slug serves to seal the kiln from the ambient atmosphere. The kiln is formed of a pair of spaced shells and means are provided for feeding combustion supporting gas into the interior of the kiln.

The discharge end of the kiln is sealed against a chimney. The combustion gases and fly ash rise in the chimney and enter an afterburner where additional burning takes place. The heavier, solid products of combustion drop onto a conveyor which is submerged in water which serves to seal the discharge end from the ambient atmosphere.

Alternatively, the discharge end of the kiln may be adjacent a large, closed pit into which the ash drops. In such a case, processing must be stopped in the event that it is necessary to remove the ash from the pit.

It is an important object of the invention to provide apparatus for disposing of solid waste in a sealed system on an essentially continuous basis.

It is a further object of the invention to provide a cylindrical kiln for use in such a system which will be efficient in operation.

It is a still further object of the invention to provide such a kiln wherein the injection of combustion supporting gas is accomplished easily and efficiently.

These and other objects features, advantages and uses will be apparent during the course of the following description when taken together with the accompany- I ing drawings wherein:

FIG. 1 is a longitudinal section of a first form of apparatus of the invention;

FIG. 2 is a sectional view taken on lines 2-2 of FIG. I, viewed in the direction of the arrows;

FIG. 3 is a sectional view taken on lines 3-3 of FIG. I, viewed in the direction of the arrows;

FIG. 4 is a view similar to that of FIG. 1 of the feed end of a kiln of the invention showing an alternative construction for sealing the feed end of the kiln;

FIG. 5 is a perspective view of the door used with the embodiment of FIG. 4;

FIG. 6 is a sectional view taken on lines 6-6 of FIG. 4, viewed in the direction of the arrows;

FIG. 7 is a side view of the door of FIG. 4 in the closed position;

FIG. 8 is a view similar to that of FIG. 1 of the discharge end of a kiln of the invention showing a spray chamber located below the secondary combustion chamber;

FIG. 9 is a veiw similar to that of FIG. 1 of a further embodiment of the apparatus of the invention for handling large quantities of waste material;

FIG. 10 is a perspective view of the elements associated with the discharge end of the apparatus of FIG. 9',

FIG. 11 is an enlarged side elevation, partly'in section, of the ash conveyor used in the embodiment of FIG. 9;

FIG. 12 is a view of an alternative construction for feeding a system of the invention used for handling high volumes of material; and

FIG. 13 is a perspective view of a battery of incinerators of the invention used for handling large volumes of solid waste.

In the drawings, wherein, for the purpose of illustration, there are shown various embodiments of the apparatus of the invention, the numeral 20 designates an embodiment of the apparatus of the invention, generally. Apparatus 20 which may be used'to process of the order of about 2000 lbs. of solid waste per hour, is seen to comprise a rotary kiln 22, a feeder 24 for feeding the kiln, a secondary combustion chamber 26 and an ash pit 28 (FIG. 1).

Kiln 22 is cylindrical and is tipped downward from its feed end 30 toward its discharge end 32. It is formed of an outer steel shell 34 and an inner refractory shell 36 of brick or similar material spaced from the outer shell 34 as shown at 38 and affixed thereto with heat insulating material as shown at 40. A plurality of openings 42 connect between the space 38 and the interior of the kiln as shown in FIG. 2. A blower-'44 feeds combustion supporting gas such as air into the space between the shells, through the openings 42 and into the interior of kiln 22. A burner 46 is utilized to ignite the solid waste material in the kiln.

Feeder 24 comprises a hopper 48 into which the solid waste is deposited by any suitable means. The material from the hopper 48 drops into the Compactor cylinder 50 where it is compressed into a slug by means of a hydraulic ram 52 which is actuated by the usual control and supply means 54 (details not shown). As ram 52 moves toward the right of FIG. 1, it compacts the material which dropped into compactor 50 from hopper 48 into a slug. When the slug exerts a minimum predetermined pressure as measured on a sensor (not shown) a door 56 moves from the first position wherein the feed end 30 is sealed closed to the dotted position (second position) shown in FIG. 1.

In this second position of door 56, the compacted slug seals feed end 30 and ram 52 pushes the slug into kiln 22. As soon as ram 52 starts to retract, door 56 moves back to its first position. Thus, it can be seen that the feed end of the kiln is kept sealed while contin- The ash, unburned solids and exhaust gases leave the discharge end 32 of the kiln 22. The heavier material drops into the pit 28 which is preferably shown as a water filled pit with the water at the level shown at 62. A conveyor 64 is mounted below the level of the water. The water seals the discharge end of the kiln from the ambient atmosphere.

FIG. 3 illustrates one construction of ash conveyor 64 which is used to remove the ash from pit 28. The conveyor is under the level 62 of the water until it is clear of the kiln so that the kiln is sealed. The ash drops onto a table 66 or into a dump truck or similar unit used for its removal. A paddle wheel 65 is used to wet the lighter floating ash particles by agitating the water near the surface. The wetted particles then drop onto the conveyor 64.

The exhaust gases and some unburned solids carried by the gases rise into secondary combustion chamber 26 which is provided with a burner which burns the unburned solids. Most of the ash burned in the secondary combustion chamber 26 drops into pit 28 and the balance is exhausted with the gases through a chimney 70.

Incinerator 80 (FIG. 4), which will process of the order of about 2,000 lbs. of solid waste per hour, is provided with a kiln 82 which is similar to kiln 22 except for the configuration at its feed end. A hopper 86 drops the solid waste into a compactor 84 which is provided with a ram 52 and a control and supply 54. It is noted that the difference between compactor 84 and compactor 50 resides in the direction of the vertical component of the feed into the kiln. The downward feed of compactor 84 makes it less likely that any material will hang up on the sill and thereby keep the door from closing.

A door 88 is controlled by means of a cylinder 90. Door '88 is raised when the slug is sufficiently compacted to thereby permit ram 52 to push the waste mathe feed is completed.

Door 88 is bifurcated at its lower end where it is provided with a pair of depending legs 94. The space between the legs 94 serves as the opening through which the kiln is fed when the door 88 is up. The bottom edge of the solid portion 96 of door 88 rests on sill 92 when the door is in its closed position (FIG. 7). The stepped shape of the sill limits the possibility that solid waste will remain on the sill rather than dropping into the kiln.

FIG. 8 illustrates a scrubber 100 located at the dis charge end of kiln 22 or kiln 80. Water from pit 28 is pumped by a pump 102 to one or more sprays 104 to wash the exhaust'gases. This washing soaks the solid particles carried by the gases and causes them to drop into pit 28. Since this procedure uses up a certain amount of water, make up is added from a supply 106 when the water drops below the level 62 as measured by a sensor 108. Make up is stopped when the level reaches that of a sensor 110, namely, level 63.

In FIGS. 9-12 there is illustrated a system of the invention for incinerating solid wastes which will process solid wastes at a rate of the order of 4,000 lbs. per hour. Apparatus 120 comprises a kiln 122 which is similar in concept and operation to those already described, a compaction section 124 and a discharge section 126. The kiln 122 is rotated by means of a motor 128 and a drive 130. It is sealed from ambient atmosphere at its feed end by a door 132 which is moved up and down by a hydraulic cylinder 134. Door 132 is similar in construction to door 88 and its operation is controlled by cylinder 134 which is similar to cylinder 90.

Compaction section 124 is seen to comprise a compaction chamber 136, a hopper 138 and a feed frame 140. Feed frame 140 (FIG. 12) supports hopper 138 and is provided with a pair of dump arms 142 which are operated by a hydrualic cylinder 144. The arms 142 grasp a mobile container 146 and raise it from the lower position shown in FIG. 12 to the upper position. In the upper position, its contents are deposited in hopper 138 from which it is delivered to the compaction chamber 136.

The compaction chamber 136 is similar to those previously described. Its ram (not shown) is controlled by a hydraulic cylinder 148. When the slug reaches a predetermined degree of compaction, door 132 is raised to permit the slug to enter kiln 122 where the initial incineration process is carried out.

The discharge section 126 is divided into several separate elements. The solid material leaving the kiln drops into a waterfilled pit 152. A pair of sprays 154 and 155 have their nozzles directed so that their streams are directed across the top of the water in the pit 152 and thereby wash the solid ash particles thereby causing them to drop into pit 152 for removal by a water submerged conveyor 156. Spray 155 also serves as a sluice to wash down the solids which collect.

The ash which drops intopit 152 is scraped from the pit by flight bars 158 which are affixed to conveyor 156. The material is carried up. the incline 161 and is deposited, for example, in a dump truck 163. Since the drive of the conveyor is well known in the art, no details of the drive means are shown.

The exhaust gases carrying some unburned solid particles'next enter a mixing chamber 150 where a change in gas velocities causes settling of the solid particles and they eventually drop into the pit 152. The gases leave the mixing chamber .150 and enter-a secondary combustion chamber which is provided with a burner 162 and a blower 164. Here, the unburned gases, smoke and odors are incinerated and are disposed of by controlled high temperatures of the order of l750-1800F with proper air distribution from blower 164. The gases are exhausted through a stack 166.

F IG. 13 is a perspective view of a system 200 utilizing the teachings of the invention for processing volumes of the order of about 8,000 lbs. of solid waste per hour. It is seen to comprise a plurality of kilns 202 which are rotated by motors 204 (one shown) and drives 206. Solid waste to be processed is delivered by, for example, a dump truck 208 to a refuse pit 210. The refuse from refuse pit 210 is moved by conveyors 214 to at least one shredder 216 where the large pieces are reduced in size. Next, the material is moved by a shredded waste conveyor 218 to a surge bin 220.

The output of the surge bin is a metered discharge through a conveyor 222 to a hopper 224. The waste is delivered from the hopper 224 to one or more compactors 226. The kiln is charged by the compactor in the same manner as has been described heretofore. The solid ash waste is removed by a conveyor 228 to, for example a dump truck 230. Secondary incineration occurs in a chamber 232 which is provided with a burner 234 and the gases are exhausted through a stack 236.

While particular embodiments of the invention have been shown and described, it is apparent to those skilled in the art that modifications are possible without departing from the spirit of the invention or the scope of the subjoined claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Apparatus for disposing of solid waste material comprising:

a cylindrical kiln having a feed end and a discharge end and rotatable about its axis, mounted such that the feed end is somewhat higher than the discharge end;

means for feeding compacted solid waste material into the kiln through the feed end thereof;

first sealing means for sealing the feed end of the kiln from the ambient environment such that a compacted slug of solid waste material may be fed to the kiln without breaking the seal;

second sealing means for sealing the discharge end of the kiln from the ambient environment;

means for rotating the kiln;

means for burning the solid waste material in the kiln;

means for introducing combustion supporting gas such as air into the kiln to thereby promote the burning of the solid waste material in the kiln;

a secondary combustion chamber mounted at the discharge end of the cylindrical kiln for incinerating those combustibles which pass through the kiln;

a stack connected to the secondary combustion chamber for removing the exhaust gases; and

collecting means for collecting solid ash which is ejected from the discharge end of-thecylindrical kiln.

2. The invention of claim 1 including:

removing means for removing such solid'ash without breaking the seal at the said discharge end of the cylindrical kiln.

3. The invention of claim 2 wherein:

the second sealing means comprises a pool of liquid just below the said discharge end of the cylindrical kiln; and I the removing means comprises a conveyor moving through the liquid pool to the ambient environment such that the liuqid serves to seal the discharge end of the cylindrical kiln while removal of the solid ash takes place on a continuous basis.

4. The invention of claim 1 wherein the first sealing means comprises:

a door movable between a first position in which the feed end of the cylindrical kiln is closed to the ambient environment and a second position in which a compacted slug of waste material of predetermined size being fed to the kiln seals the said feed end as the door is opened to receive the said slug.

5. The invention of claim 1 wherein the cylindrical V kiln comprises:

an outer steel shell;

an inner refractory shell spaced from the outer steel shell;

the inner refractory shell having a plurality of openings therein leading from the space between the outer steel shell and the inner refractory shell to the interior of the cylindrical kiln forming the means for introducing combustion supporting gas or air into the cylindrical kiln.

6. The invention of claim 1 wherein:

the secondary combustion chamber is provided with an afterburner mounted above the discharge end of the cylindrical kiln for burning any unburned solid particles carried by the exhaust gases.

7. The invention of claim 6 including:

a spray chamber mounted above the discharge end of the cylindrical kiln and below the secondary combustion chamber;

at least one spray nozzle mounted in the spray chamber for wetting the solid ash particles carried in the exhaust gases and causing said particles to drop below the discharge end of the cylindrical kiln. 

1. Apparatus for disposing of solid waste material comprising: a cylindrical kiln having a feed end and a discharge end and rotatable about its axis, mounted such that the feed end is somewhat higher than the discharge end; means for feeding compacted solid waste material into the kiln through the feed end thereof; first sealing means for sealing the feed end of the kiln from the ambient environment such that a compacted slug of solid waste material may be fed to the kiln without breaking the seal; second sealing means for sealing the discharge end of the kiln from the ambient environment; means for rotating the kiln; means for burning the solid waste material in the kiln; means for introducing combustion supporting gas such as air into the kiln to thereby promote the burning of the solid waste material in the kiln; a secondary combustion chamber mounted at the discharge end of the cylindrical kiln for incinerating those combustibles which pass through the kiln; a stack connected to the secondary combustion chamber for removing the exhaust gases; and collecting means for collecting solid ash which is ejected from the discharge end of the cylindrical kiln.
 2. The invention of claim 1 including: removing means for removing such solid ash without breaking the seal at the said discharge end of the cylindrical kiln.
 3. The invention of claim 2 wherein: the second sealing means comprises a pool of liquid just below the said discharge end of the cylindrical kiln; and the removing means comprises a conveyor moving through the liquid pool to the ambient environment such that the liuqid serves to seal the discharge end of the cylindrical kiln while removal of the solid ash takes place on a continuous basis.
 4. The invention of claim 1 wherein the first sealing means comprises: a door movable between a first position in which the feed end of the cylindrical kiln is closed to the ambient environment and a second position in which a compacted slug of waste material of predetermined size being fed to the kiln seals the said feed end as the door is opened to receive the said slug.
 5. The invention of claim 1 wherein the cylindrical kiln comprises: an outer steel shell; an inner refractory shell spaced from the outer steel shell; the inner refractory shell having a plurality of openings therein leading from the space between the outer steel shell and the inner refractory shell to the interior of the cylindrical kiln forming the means for introducing combustion supporting gas or air into the cylindrical kiln.
 6. The invention of claim 1 wherein: the secondary combustion chamber is provided with an afterburner mounted above the discharge end of the cylindrical kiln for burning any unburned solid particles carried by the exhaust gases.
 7. The invention of claim 6 including: a spray chamber mounted above the discharge end of the cylindrical kiln and below the secondary combustion chamber; at least one spray nozzle mounted in the spray chamber for wetting the solid ash particles carried in the exhaust gases and causing said particles to drop below the discharge end of the cylindrical kiln. 